What is Wilson disease?

Wilson disease is a rare genetic condition that affects about one in 30,000 people. Wilson disease causes a person's body to store too much of the mineral copper. Many foods contain copper, and it is important for people to have a small amount of copper in the body. However, high levels of copper can damage organs in the body.

In Wilson disease, copper builds up in the liver, brain, eyes and other organs. Over time, the extra copper can lead to organ damage that may cause death.

How is Wilson disease diagnosed?

Doctors diagnose Wilson disease through a physical exam and laboratory tests. The physical examination focuses on signs of liver disease as well as neurologic function.

The exam includes the use of a special light, called a slit lamp, to look for Kayser-Fleischer rings in a person's eyes. Kayser-Fleischer rings are found in almost all people with Wilson disease who show signs of neurologic damage. They are found in about half of people who have only signs of liver damage. Kayser-Fleischer rings do not harm a person's vision.

Doctors also order lab tests to measure the amount of copper in the blood and urine. Most people with Wilson disease will have lower-than-normal levels of copper in the blood, as well as lower blood levels of a protein called ceruloplasmin, a protein which contains copper. However, in people with acute liver failure caused by Wilson disease, copper levels in the blood are often higher than normal. Urine is collected over a 24 hour period to look for increased copper levels typical of Wilson disease.

In addition, a special procedure called a liver biopsy using a needle is done to remove a small piece of a person's liver. The liver sample is then examined under a microscope to look for damage found in Wilson disease. Copper content of the liver is also measured.

Genetic testing is frequently used to help diagnose Wilson disease in some people and is important for reliable early diagnosis of brothers and sisters of a patient with Wilson disease.

How is Wilson disease treated?

When Wilson disease is diagnosed early and treated effectively, people with the condition usually can have good health.

However, for patients who have severe cirrhosis, acute liver failure or other serious liver disorders, a liver transplant may be the only option for treatment.

People who have Wilson disease must be treated throughout their lives to lower and control the amount of copper in their bodies. When Wilson disease is diagnosed early and treated effectively, people with the condition usually can enjoy good health.

The first steps in treatment of Wilson disease involve:

Removing the excess copper from the body.

Reducing intake of foods that are rich in copper.

Treating any liver or central nervous system damage.

Doctors currently use two drugs to treat Wilson disease: D-penicillamine (Cuprimine) and trientine (Syprine). These drugs help remove copper from organs and release it into the bloodstream. Once the copper enters the bloodstream, it is filtered out by the kidneys and excreted in urine.

Both drugs carry the possibility of major side effects. The drugs can worsen neurologic symptoms because the copper released into the bloodstream may sometimes be taken back up by the central nervous system. In addition, about one-quarter to one-third of people treated with D-penicillamine will experience other reactions to the medication, such as fever, rash and effects on the kidneys and bone marrow. The risks associated with trientine appear to be lower.

If they are pregnant, women with Wilson disease are given lower doses of these drugs to reduce the risk of having a baby with birth defects. Lower doses also improve the body's ability to heal if surgery is done during childbirth.

Zinc is another therapy for Wilson disease. Given in the form of zinc salts, such as zinc acetate (Galzin), it keeps the digestive tract from absorbing copper. Because zinc removes copper rather slowly, it usually is given as maintenance therapy for Wilson disease. It appears safe to use a full dose of zinc during pregnancy.

Once the symptoms of Wilson disease have improved and tests show that a person's copper levels have been lowered to a safe level, maintenance treatment begins. This can be with D-penicillamine or trientine or zinc. Blood and urine are routinely tested to make sure that copper remains at a safe level.

Doctors often recommend that people with Wilson disease reduce the amount of copper in their diets. Specifically, they are instructed to avoid liver or shellfish, which may contain high levels of copper. During initial treatment, patients may also be told not to eat other copper-rich foods, such as mushrooms, nuts, and chocolate. Once people begin maintenance treatment, they may be able to eat these foods in moderation. In addition, people with Wilson disease should avoid multivitamins that contain copper and have their drinking water checked for copper content.

Is Wilson disease inherited?

Yes. Wilson disease is inherited in what doctors call an autosomal (not on the X chromosome) recessive pattern. In this pattern of inheritance, a person needs to inherit two altered (mutated) copies of a gene - one from each parent - to develop the disease. The parents of a person with Wilson disease each carry one mutated copy of the gene and one normal copy of the gene, so they do not show signs or symptoms of the disease. Doctors refer to such people as "carriers."

With each pregnancy, couples who are carriers of the gene for Wilson disease face a 25 percent chance of having a child who will develop Wilson disease. Such a couple also has a 50 percent chance of having a child who is a carrier for Wilson disease and a 25 percent chance of having an unaffected child with two normal copies of the gene.

A clinical trial supported by the NIH recently found a new drug, tetrathiomolybdate (Coprexa), to be as effective as trientine hydrochloride in removing copper and to pose less risk of neurologic side effects. The U.S. Food and Drug Administration is now evaluating the drug.

Additional Resources for Wilson disease

Wilson Disease [digestive.niddk.nih.gov]From the National Digestive Diseases Information Clearing House

Wilson Disease [rarediseases.info.nih.gov] From From The Genetic and Rare Diseases Information Center (GARD), a collaborative effort of two agencies of the National Institutes of Health, The Office of Rare Diseases Research (ORDR) and the National Human Genome Research Institute (NHGRI).